This artist ([link]) wrote they used photoshop and painttool sai. i have never heard of painttool sai but i have heard a lot about photoshop. which one is better and how did this artist use both?? i don't get it.
SAI is properly a drawing application, but special effects should be done in a separate program like photoshop.
People usually draw all the stuff in sai, ink it in sai, color it in sai, almost finish it in sai, and then load it in photoshop and use a couple of filters.
I use different programs depending on what I want to draw i have pain tool sai and i love it photoshop CS5 for details and background artrage when i want it to have a traditional look and illustrator for vectors and smooth lineart
A lot of people have given you good advices, so I will just add how I use them~
I find Sai to be wonderful for coloring and lineart. It works super smooth withough lagging and is easy to understand. However, Photoshop is very useful for effects, so that way it is useful aswell.
SAI is a sweet tool in that it has a very small memory footprint. (Hardly ever lags and has a nice stabilizing tool for linework.) Photoshop is the industrial workhorse. It is the main one used out there because it has a strong connection with educational institutions and training programs. And, before I forget, Photoshop is going to be the one which is most costly (plus newer versions of the program run really slow on older computers).
Sai is great for drawing because it's lightweight and in my experience, rarely hangs or lags. But you can't expect Sai to do a great job at color correction or giving your pieces a "finished" look. Photoshop, on the other hand, can support the sketch to the finished product.
Personally, I prefer Sai for sketching, inking and coloring. I only ever use Photoshop to correct things.
If you like simpler programs, use SAI. I agree with what everyone said about it being easier to blend with SAI, and I'll also pitch in and say that there seems to more brush options in SAI. Unless I'm an unaware Photoshop n00b lol I heard that it's better to use the circle shaped color slider, which Photoshop doesn't have because it's easier to view complementary colors that way, or something like that...
Sai can work with photoshop files, not the other way around. I use Sai and Photoshop together pretty much all the time. I don't really have a specific reason why I use one or the other beyond "X feels easier to do in Y program".
I personally use both as well. I prefer painting in SAI because it's waaaay faster than photoshop. It doesn't take so much memory from your computer, and it's easier to mix colors. I use photoshop to clean up my mess, apply textures, change colors and add effects.
thanks!